Rock drill drive



4 Sheets-Sheet l ATTORNEY March 7, 1967 E. H. KURT ROCK DRILL DRIVE Filed Deo. 4, 1964 March 7, 1967 E. H. KURT 3,307,638

ROCK DRILL DRIVE Filed Dec. 4, 1964 4 Sheets-Sheet 2 I NVENTOR.

EWL H. KURT @am w .Tm

ATTORNEY E. H. KURT ROCK DRILL DRIVE March 7, 196'? 4 Sheets-Sheet 3 Filed Deo. 4, 1964 INVENTOR EWAL H. KURT @M MTW ATTORNEY arch'; 19,67Ik E H KURT 33076138 ROCK DRILL DRIVE Filed Deo, 4,A 1964 4 sheets-sheet 4 YFIG. 6

INVENTOR. EWL H. KURT @M w ATTORNEY United States Patent 3,307,638 ROCK DRILL DRIVE Ewald H. Kurt, Phillipsburg, NJ., assignor to Ingersoll- Rand Company, New York, N.Y., a corporation of New Jersey Filed Dec. 4, 1964, Ser. No. 415,916 15 Claims. (Cl. 173-105) This invention relates to rock drills and the like and has particular reference to the provision of a new and improved rotation means for supplying intermittent rotation to the working implement of a rock drill of the type in which the working implement is capable of rotary movement independently of the drill piston.

Conventionally, the drill steel and bit which comprise the working implement of a rock drill which includes an independently rotatable workin-g implement generally are rotated continuously throughout the operation of the drill. This continuous rotation is, however, undesirable and often results in destruction of said working implement. More specifically, as said rotation is continuous throughout impact and immediately thereafter, it causes the bit and drill steel threads to become extremely tight and result-s in galling which leads to excessive Wear and, in many instances, even tool fracture.

An object of the present invention is to provide a new and improved rotation means for supplying intermittent rotationvto the working implement of a rock drill of the type in which the working implement is capable of rotary movement independently of the drill piston.

Another object of the present invention is to provide a new and improved rotation means of the type set forth which is adapted to prevent rotation of said working implement during impact.

Another object is to provide a new and improved rotation means of the type set forth which is adapted to provide the drill working implement with a longer useful life than is conventional.

Another object is to provide a new and improved rotation means of the type set forth which is of rugged construction and is positive in operation. y

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings. It will be understood that changes may be made in the details of construction and arrangement of parts shown and described as the preferred forms of the invention has been given by way of illustration only.

Referring to the drawings:

FIG. l is a longitudinal sectional view of a rock drill constructed in accordance with the present invention showing the drill piston at the top of its stroke;

FIG. 2 is a longitudinal sectional view generally similar to that of F-IG. l but showing the drill piston on its downstroke;

lFIG. 3 is a fragmentary, sectional view illustrating the details of construction of the valve means shown in FIGS. 1 and 2;

iFlG. 4 is a sectional view taken on line 4-4 of FIG. 3 looking in the direction of the arrows and illustrates the motive meansl for supplying rotative movement to the drill steel;

FIG. 5 is a perspective view of a drill piston constructed in accordance with the present invention; and

FIG. 6 is a fragmentary, partially sectional view of a modified form of the invention.

Referring more particularly to the drawings wherein similar reference characters designate corresponding parts throughout the several views, FIG. 1 illustrates a rock drill designated generally at 10 which includes the drill housing 11.

ICC

Drill housing 1'1 is bored to provide a piston chamber 12 having a free exhaust port 13 and containing a reciprocatory hammer piston 14 that controls said exhaust port 13. The piston 14, as' illustrated, includes a head 15 having a circumferentially grooved or cut-away portion 116 and a stern 17 that extends slidably into the reduced portion 12a of piston chamber 12.

Drill housing 11 further includes a drill steel bore or passage 18 forwardly of the piston chamber 12 and in operative communication therewith. Drill steel bore 18 contains a drill steel 19' which is provided with Shanks 20 and adapted to be urged forwardly by the hammer piston 14 upon contact with the stem 17 thereof.

A hollow tubular rod member 21 is operatively connected to a mounting member 22 adjacent to, and externally of, the rearwardly extending end of drill housing 11. Tubular member 21 extends into the drill housing 11 through pasage means 23 therein and passes through hammer piston 14 and into drill steel 19. Member 21 may be adapted to admit pressurized fluid to the cutting surface. Alternatively, as it forms no portion of the present invention, member 21 may be adapted to draw cuttings' from the cutting surface externally of the rock drill 1G or may be utilized for any other purpose for which it might be suitable.

The valving means for effecting actuation of the hammer piston 14 comprises a, spool-type valve 24 which is positioned within a valve chamber 25 formed within drill housing 11 rearwardly of the piston chamber 12. Valve chamber 25 communicates through fluid passage means 26 with the fluid inlet 27 of the rock drill 10 such that pressurized fluid admitted to the rock drill 10 through said iluid inlet 27 is introduced to the spool-type valve 2'4.

Spool-type valve 24, more particularly, comprises a valve chest 28 which is formed by valve plates 29, 30, 31, and 32, said latter plate 32 being disposed at the forward end of the valve chamber 25 and serving as a bound-ing surface for the rearward end of piston chamber 12. Valve plates 29 and 30 are so constructed and arranged as to define annular recesses 33 and 34 which are operatively connected through'iluid passage means 315, 36, and 38V within the Walls of drill housing 11 to piston chamber 12. Valve plate 32 includes a pair of fluid openings 32a and 32h which serve to communicate presurized iluid from valve chamber 25 to piston chamber 12; and valve plate 31 is sl-idably mounted relative to valve plates 29, 30, and 32 and includes an extern-a1 flange 37 which is disposed within said annular recess 33. The valve plate 31 serves to control the flow of pressurized dluid through said fluid openings 32a and 32h and also through the fluid passage 38 which operatively connects spool-type valve 24 with piston chamber 12 such as to control piston 14 upon its return stroke.

In the operation of spool-type valve 24, pressurized fluid entering piston chamber 12 through lluid passage 38 and fluid openings 32a and 32b actuates the upward and downward movement, respectively, of piston 14; and fluid escaping from said piston chamber 12 through fluid passage means 35 and 36 actuates said spool-type valve 24 such as to control the ilow of fluid through said actuating means. Flu-id admitted to said piston chamber 12 is permitted to escape therefrom during the operation of the valve through exhaust port 13.

A fluid-powered motor, such as the air mot-or 39, is provided for supplying drill steel 19 with rotary motion independently of the piston 14. Motor 39 is carried within a motor chamber 40 formed within a housing member 41 whichl is operatively associated with the drill housing 11. Motor 39, as illustrated in FIG. 4, is of the gear type and comprises a plurality of gears 42 which are keyed to` the rotatably journalled shafts 43 and 43a, respectively, within motor chamber 40. The chamber 40 is operatively connected through fluid passage means 44 to a forward rotation fluid input hose 45 and is directly connected through fluid passage means 46 to the reverse rotation fluid input hose 47. Hoses 45 and 47 are operat1vely connected at their free ends to a source of pressurized fluid.

The motor 39, furthermore, is operatively connected to drill steel 19 to effect independent intermittent rotation thereof through a reduction gearing system. This reduction gearing comprises a gear means 48 formed upon the end of shaft 43, a gear means 49 upon a rotatably journalled shaft 50 in meshing engagement with said gear means 48, and a second gear means 51 upon said shaft 50 in operative relation to said lgear means 49. Gear means 52 formed upon a rotatable portion 53 of drill housing 11 operatively meshes with said second gear means 51 to transmit rotary movement to said housing portion 53. As illustrated, said rotary movement is transmitted from said gear means 52 to drill steel 19 through the action of driving and driven members 54 and 55, respectively, which are rotatably driven by the rotatable portion 53 of drill housing 11 land drivingly engage the Shanks 20 of drill steel 19. Alternatively, however, other forms of connection, such as a spline-type connection, could be utilized to operatively connect said drill steel 19 with motor 39.

The present invention comprises the provision of means whereby rotation of drill steel 19 may be automatically cut off prior to impact and recommenced after said impact.

More specifically, the valve means 56 is interposed between input hose 4S and the fluid passage means 44 which supplies pressurized lfluid to more 39 during the forward rotation thereof. The valve means 56, as illustrated in FIGS. 1 through 3, comprises a valve chamber 58 formed within the housing member 41 in direct communication with said fluid passage means 44 and hose 45, the valve chamber 58 directly communicating at one of its ends with a source of pressurized fluid independent of the fluid inlet 27 through the fluid hose means 59. The fluid hose means 59 may be provided with manual control means (not shown) for providing complete control over the fluid passing therethrough.

A valving member 60 is operatively positioned Within the valve chamber 58 by a spring or similiar resilient member 61 which is connected adjacent its opposite ends to the valve member 60 and the spring seat 64 formed in a wall of the housing member 41. Spring 61 is adapted to pass into a hollowed-out portion 62 of the valve member 60 in its compressed state.

With the rock drill in operation, the spring 61 is adapted to be in an uncompressed state and to force the valving member 60 towards the end of the valve chamber 58 communicating with the hose means 59. The valving member 60, as will be seen from FIGS. 1 and 2, is adapted to close the fluid passage means 44 to prevent fluid flow therethrough to the motor 39 when the spring 61 is in its uncompressed state. When pressurized air is admitted to the valve chamber 58 through the hose means 59, however, said pressurized air overcomes the force of spring 61 and forces the valving member 60 towards the spring seat 64, thereby compressing said spring 61 and opening the uid passage means 44 to direct communication with the input hose 45.

An alternative embodiment of the valve means 56 is illustrated in FIG. 6. In this alternative construction, the valve chamber 58a directly communicates at one of its ends with the fluid inlet 27 through the fluid passage means 59a. The opposite end of the valve chamber 58a is closed off by a threaded closure member 64a, and the spring or resilient member 61a is connected adjacent its opposite ends to the closure member 64a and the hollowed-out portion 62a of the valving member 60a. The

spring 61a normally maintains the valving member 60a adjacent the end of valve chamber 58a which communicates ywith the fluid passage means 59a. During the operation of the rock drill 10, however, air admitted to the valve chamber 58a overcomes the force of the spring 61a and interposes the valving member 60a between the fluid hose 45 and the fluidpassage means 44 to prevent d1rect fluid communication therebetween.

Second fluid transmitting means are provided for pern mitting flow of fluid from input hose 45 to the motor 39 during a portion of the drilling operation and are lllus= trated in detail in FIGS. l and 2. Said second fluid tfans= mitting means comprises fluid passage means 65 formed within housing member 41 in direct communication with valve means 56 and fluid passage means 66 circumferen= tially disposed within the drill housing 11 and conmni= eating with said passage means 65. 4

The stern 17 of hammer piston 14, as will be seen from FIG. 4, is provided with an external circumferential,- n`= dercut or grooved portion 67 which isvadaptd to come munioate with said passage means 66 when the piston 14 is at, or adjacent to, the top of its stroke. The lindereut portion 67 of said piston 14 serves to eor'nrn'uniate fluid from the passage means 66 to cooperating passage means 68 and 69 in housing 11 and housing member 41, :respecf tively, and completes the fluid bypass to motor 39;

From the foregoing, it will be seen that,- as the under: cut portion 67 of piston 14 forms a portion of tli fluid passa-ge to motor 39, during the operation of rock drill 10 the positioning and width of said undercutpor'tion I67 control the time length of fluid flow to said motor 39 and, hence, the time length of rotation -of drin steel 19; More specifically, with 'reference to the drill steel 19, it will be seen that rotation of the'latter is permitted only when the piston 14 is at, or adjacent -topthve top of its stroke. In this manner, rotation of said drill s'tel 19 is' eliminated during, and adjacent to, impact suoli that the before-stated -objects of the invention are accomplished. Furthermore, as the width and positioning of said linder-l cut portion 67 control said period of rotation of said drill steel 19, it will be seen that the cutoff 4and cut-in points of steel rotation may he controlled as desired through the `proper dimensioning and positioning of said under cut portion 67.

In the operation of the rock drill 10, with the hammer piston 14 at the top of its stroke, pressurized fluid from hose 45 passes through valve means 56 and flows through the fluid passage formed by passage means 65, 66, 68, and 69 and undercut portion 67 of said piston 14 to actuate the motor 39. Motor 39, then, through the before-described reduction gearing system effects rotation of drill steel 19.

As piston 14 is urged downwardly towards impact with drill steel 1'9, undercut portion 67 of said hammer piston 14 moves out of communication with passage means 66 and 68 until, at some point before impact, it is completely out of communication with said passage means 66 and 68 and the fluid passage to motor 39 is broken thereby effecting de-actuation of said motor 39. In such manner, drill steel 19 is removed from rotary movement until said undercut portion 67 of piston 14 again approaches its top-of-stroke position land communication :between passage means 66 and 68 and said undercut portion 67 is reestablished.

From the fore-going, it will be seen that I have provided new and improved means for `accomplishing all of the objects and advantages of the invention.

I claim:

1. In a rock drill including a housing having a bore, piston means disposed within said bore for longitudinal movement therein, and means for controlling said longitudinal movement of said piston means:

(a) drill steel means associated with said piston means such as to be urged longitudinally thereby during said longitudinal movement of said piston means;

(b) fluid-operated motor means;

(c) fluid passage means operatively connecting said motor means with a source of motive fluid;

(d) said fluid passage means including a first fluid passage having a portion thereof formed in said piston means and communicating fluid through said first fluid passage during only a portion of said longitudinal movement of said piston means; and

(e) means operatively connecting said motor means with said drill steel means such that actuation of said motor means by said motive fluid effects rotary movement of said drill steel means.

2. A rock drill accor-ding to claim 1 wherein said portion of said first fluid passa-ge formed in said piston means comprises a circumferential groove about said piston means.

3. A rock drill according to claim 2 wherein said circumferential groove is positioned upon said piston means to communicate fluid to said motor means with said drill steel longitudinally spaced from said piston means.

4. A rock drill .according to claim 1 wherein said drill steel means is forwardly of said piston means and said portion of said first fluid passage upon said piston means is positioned thereon to communicate fluid through said first fluid passage only when said piston means is adjacent its most rearwardly position.

5. A rock drill according to claim 1 wherein said drill steel means is forwardly of said piston means and said portion of said first fluid passage upon said piston means comprises a groove disposed circumferentially around said piston means for communicating fluid through said first fluid passage when said piston means is adjacent its most rearwardly position.

6. A rock drill according to claim 1 wherein said drill steel means is forwardly of said piston means, said piston means comprises a piston head and a piston stem and said portion of said first fluid passage on said piston means comprises a fluid channel circumferentially around said piston stem and communicating fluid to said motor means with said piston means adjacent its most rearwardly position.

7. In a rock drill including a housing having a bore, piston means disp-osed within said bore for longitudinal movement therein, and means for controlling said 1ongitudinal movement of said piston means:

(a) drill steel means associated with said piston means to be urged longitudinally thereby during said longitudinal movement of s-aid piston means;

(b) fluid-operated motor means;

(c) uid passage means operatively connecting said motor means with a source of motive fluid;

(d) said fluid passage means including a first fluid passage having a portion thereof formed in said piston means and communicating fluid through said first flui-d passage during only a portion of said longitudin-al movement of said piston means;

(e) said fluid passage means including a second fluid passage independent of said piston means and directly connecting said motor means and said source of motive fluid;

(f) valve means interposed between and connecting said first and second fluid passages, said valve means closing off said second fluid passage during the longitudinal movement of said piston means; and

(g) means operatively connecting said motor means with said drill steel means such that actuation of said motor means iby said motive fluid effects rotary movement of said drill steel means.

8. A rock drill according to claim 7 wherein said drill steel means is forwardly of said piston means and said portion of said first fluid passage upon said piston means is positioned thereon to communicate fluid through said first fluid passage only when said piston means is adjacent its most rearwardly longitudinal position.

9. A rock drill according to claim 7 wherein said `drill steel means i-s forwardly of said piston means and said portion of said first fluid passage upon said piston means comprises a circumferentially disposed groove around said piston means to communicate fluid through said first fluid passage when said piston means is adjacent its most rearwardly longitudinal position.

10. A rock drill according to claim 7 wherein said portion of said first fluid passage upon said piston means comprises a circumferentially disposed undercut portion upon said piston means and communicating fluid through said first fluid passage with said piston means displaced longitudinally from said -drill steel means.

11. In a rock drill including a housing having a bore, a hammer piston longitudinally movable within said bore, and means for actuating said longitudinal movement of said piston:

(a) a drill steel forwardly of and in alignment with said piston;

(b) said drill steel being longitudinally movable upon impact with said piston;

(c) a fluid-operated motor;

(d) a first fluid passage operatively connecting said motor with a source of pressurized motive fluid;

(e) a portion of said first fluid passage being upon said piston and intermittently carrying said motive fluid to said motor during said longitudinal movement of said piston;

(f) a second fluid passage directly connecting said motor with said source of motive fluid throughout the longitudinal movement of -said piston;

(g) a fluid-actuated valve interposed within and connecting said first and second fluid passages;

(h) said Valve closing off said second fluid passage throughout the longitudinal movement of said piston; and

(i) mean-s operatively connecting said motor with said drill steel and transmitting movement of said motor into rotary movement of said drill steel.

12. A rock drill according to claim 11 wherein said connecting means between said motor and said drill steel comprises first gear means associated with said motor and second gear means associated with said drill steel, said first and second gear means bein-g in operative engagement.

13. A rock drill according to claim 11 wherein said piston actuating means is fluid operated and passage means operatively communicate the fluid system of said actuating means and said valve and supply motive fluid for operating said valve to close said second fluid passage.

14. A rock drill according to claim 11 wherein said portion of said first fluid passage upon said piston comprises a circumferentially disposed gro-ove externally around said piston and communicating fluid through said first fluid-passage when said piston is adjacent its extreme rearward position.

15. A rock drill according to claim 11 wherein said piston comprises a piston head and a piston stern and said portion of said first fluid passage on said piston comprises a fluid channel circumferentially around said piston stem and communicating fluid to said motor with said piston adjacent its most rearward position within said bore.

References Cited by the Examiner UNITED STATES PATENTS 1,488,538 4/1924 Hansen 173-105 1,982,656 12/ 1934 Gilman 173-105 2,108,989l 2/1938 Mack 173-107 3,157,237 11/1964 Kurt 173-105 3,166,131 1/1965 Worman 173-105 FRED C. MA'ITERN, .T R., Primary Examiner. L. P. KESSLER, Assistant Examiner. 

1. IN A ROCK DRILL INCLUDING A HOUSING HAVING A BORE, PISTON MEANS DISPOSED WITHIN SAID BORE FOR LONGITUDINAL MOVEMENT THEREIN, AND MEANS FOR CONTROLLING SAID LONGITUDINAL MOVEMENT OF SAID PISTON MEANS: (A) DRILL STEEL MEANS ASSOCIATED WITH SAID PISTON MEANS SUCH AS TO BE URGED LONGITUDINALLY THEREBY DURING SAID LONGITUDINAL MOVEMENT OF SAID PISTON MEANS; (B) FLUID-OPERATED MOTOR MEANS; (C) FLUID PASSAGE MEANS OPERATIVELY CONNECTING SAID MOTOR MEANS WITH A SOURCE OF MOTIVE FLUID; (D) SAID FLUID PASSAGE MEANS INCLUDING A FIRST FLUID PASSAGE HAVING A PORTION THEREOF FORMED IN SAID PISTON MEANS AND COMMUNICATING FLUID THROUGH SAID FIRST FLUID PASSAGE DURING ONLY A PORTION OF SAID LONGITUDINAL MOVEMENT OF SAID PISTON MEANS; AND (E) MEANS OPERATIVELY CONNECTING SAID MOTOR MEANS WITH SAID DRILL STEEL MEANS SUCH THAT ACTUATION OF SAID MOTOR MEANS BY SAID MOTIVE FLUID EFFECTS ROTARY MOVEMENT OF SAID DRILL STEEL MEANS. 